Audit logging for network security - Network security | Networking

Audit configuration
Audit logging
AdminNetworkPolicy audit logging
BaselineAdminNetworkPolicy audit logging
Configuring egress firewall and network policy auditing for a cluster
Enabling egress firewall and network policy audit logging for a namespace
Disabling egress firewall and network policy audit logging for a namespace
Additional resources

The OVN-Kubernetes network plugin uses Open Virtual Network (OVN) access control lists (ACLs) to manage AdminNetworkPolicy, BaselineAdminNetworkPolicy, NetworkPolicy, and egressFirewall objects. Audit logging exposes allow and deny ACL events for NetworkPolicy, egressFirewall and BaselineAdminNetworkPolicy custom resources (CR). Logging also exposes allow, deny, and pass ACL events for AdminNetworkPolicy (ANP) CR.

Audit logging is available for only the OVN-Kubernetes network plugin.

Audit configuration

The configuration for audit logging is specified as part of the OVN-Kubernetes cluster network provider configuration. The following YAML illustrates the default values for the audit logging:

Audit logging configuration

apiVersion: operator.openshift.io/v1
kind: Network
metadata:
  name: cluster
spec:
  defaultNetwork:
    ovnKubernetesConfig:
      policyAuditConfig:
        destination: "null"
        maxFileSize: 50
        rateLimit: 20
        syslogFacility: local0

The following table describes the configuration fields for audit logging.

Table 1. `policyAuditConfig` object
Field	Type	Description
`rateLimit`	integer	The maximum number of messages to generate every second per node. The default value is `20` messages per second.
`maxFileSize`	integer	The maximum size for the audit log in bytes. The default value is `50000000` or 50 MB.
`maxLogFiles`	integer	The maximum number of log files that are retained.
`destination`	string	One of the following additional audit log targets: `libc` The libc `syslog()` function of the journald process on the host. `udp:<host>:<port>` A syslog server. Replace `<host>:<port>` with the host and port of the syslog server. `unix:<file>` A Unix Domain Socket file specified by `<file>`. `null` Do not send the audit logs to any additional target.
`syslogFacility`	string	The syslog facility, such as `kern`, as defined by RFC5424. The default value is `local0`.

Audit logging

You can configure the destination for audit logs, such as a syslog server or a UNIX domain socket. Regardless of any additional configuration, an audit log is always saved to /var/log/ovn/acl-audit-log.log on each OVN-Kubernetes pod in the cluster.

You can enable audit logging for each namespace by annotating each namespace configuration with a k8s.ovn.org/acl-logging section. In the k8s.ovn.org/acl-logging section, you must specify allow, deny, or both values to enable audit logging for a namespace.

A network policy does not support setting the Pass action set as a rule.

The ACL-logging implementation logs access control list (ACL) events for a network. You can view these logs to analyze any potential security issues.

Example namespace annotation

kind: Namespace
apiVersion: v1
metadata:
  name: example1
  annotations:
    k8s.ovn.org/acl-logging: |-
      {
        "deny": "info",
        "allow": "info"
      }

To view the default ACL logging configuration values, see the policyAuditConfig object in the cluster-network-03-config.yml file. If required, you can change the ACL logging configuration values for log file parameters in this file.

The logging message format is compatible with syslog as defined by RFC5424. The syslog facility is configurable and defaults to local0. The following example shows key parameters and their values outputted in a log message:

Example logging message that outputs parameters and their values

<timestamp>|<message_serial>|acl_log(ovn_pinctrl0)|<severity>|name="<acl_name>", verdict="<verdict>", severity="<severity>", direction="<direction>": <flow>

Where:

<timestamp> states the time and date for the creation of a log message.
<message_serial> lists the serial number for a log message.
acl_log(ovn_pinctrl0) is a literal string that prints the location of the log message in the OVN-Kubernetes plugin.
<severity> sets the severity level for a log message. If you enable audit logging that supports allow and deny tasks then two severity levels show in the log message output.
<name> states the name of the ACL-logging implementation in the OVN Network Bridging Database (nbdb) that was created by the network policy.
<verdict> can be either allow or drop.
<direction> can be either to-lport or from-lport to indicate that the policy was applied to traffic going to or away from a pod.
<flow> shows packet information in a format equivalent to the OpenFlow protocol. This parameter comprises Open vSwitch (OVS) fields.

The following example shows OVS fields that the flow parameter uses to extract packet information from system memory:

Example of OVS fields used by the flow parameter to extract packet information

<proto>,vlan_tci=0x0000,dl_src=<src_mac>,dl_dst=<source_mac>,nw_src=<source_ip>,nw_dst=<target_ip>,nw_tos=<tos_dscp>,nw_ecn=<tos_ecn>,nw_ttl=<ip_ttl>,nw_frag=<fragment>,tp_src=<tcp_src_port>,tp_dst=<tcp_dst_port>,tcp_flags=<tcp_flags>

Where:

<proto> states the protocol. Valid values are tcp and udp.
vlan_tci=0x0000 states the VLAN header as 0 because a VLAN ID is not set for internal pod network traffic.
<src_mac> specifies the source for the Media Access Control (MAC) address.
<source_mac> specifies the destination for the MAC address.
<source_ip> lists the source IP address
<target_ip> lists the target IP address.
<tos_dscp> states Differentiated Services Code Point (DSCP) values to classify and prioritize certain network traffic over other traffic.
<tos_ecn> states Explicit Congestion Notification (ECN) values that indicate any congested traffic in your network.
<ip_ttl> states the Time To Live (TTP) information for an packet.
<fragment> specifies what type of IP fragments or IP non-fragments to match.
<tcp_src_port> shows the source for the port for TCP and UDP protocols.
<tcp_dst_port> lists the destination port for TCP and UDP protocols.
<tcp_flags> supports numerous flags such as SYN, ACK, PSH and so on. If you need to set multiple values then each value is separated by a vertical bar (|). The UDP protocol does not support this parameter.

For more information about the previous field descriptions, go to the OVS manual page for ovs-fields.

Example ACL deny log entry for a network policy

2023-11-02T16:28:54.139Z|00004|acl_log(ovn_pinctrl0)|INFO|name="NP:verify-audit-logging:Ingress", verdict=drop, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:81:02:01,dl_dst=0a:58:0a:81:02:23,nw_src=10.131.0.39,nw_dst=10.129.2.35,nw_tos=0,nw_ecn=0,nw_ttl=62,nw_frag=no,tp_src=58496,tp_dst=8080,tcp_flags=syn
2023-11-02T16:28:55.187Z|00005|acl_log(ovn_pinctrl0)|INFO|name="NP:verify-audit-logging:Ingress", verdict=drop, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:81:02:01,dl_dst=0a:58:0a:81:02:23,nw_src=10.131.0.39,nw_dst=10.129.2.35,nw_tos=0,nw_ecn=0,nw_ttl=62,nw_frag=no,tp_src=58496,tp_dst=8080,tcp_flags=syn
2023-11-02T16:28:57.235Z|00006|acl_log(ovn_pinctrl0)|INFO|name="NP:verify-audit-logging:Ingress", verdict=drop, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:81:02:01,dl_dst=0a:58:0a:81:02:23,nw_src=10.131.0.39,nw_dst=10.129.2.35,nw_tos=0,nw_ecn=0,nw_ttl=62,nw_frag=no,tp_src=58496,tp_dst=8080,tcp_flags=syn

The following table describes namespace annotation values:

Table 2. Audit logging namespace annotation for `k8s.ovn.org/acl-logging`
Field	Description
`deny`	Blocks namespace access to any traffic that matches an ACL rule with the `deny` action. The field supports `alert`, `warning`, `notice`, `info`, or `debug` values.
`allow`	Permits namespace access to any traffic that matches an ACL rule with the `allow` action. The field supports `alert`, `warning`, `notice`, `info`, or `debug` values.
`pass`	A `pass` action applies to an admin network policy’s ACL rule. A `pass` action allows either the network policy in the namespace or the baseline admin network policy rule to evaluate all incoming and outgoing traffic. A network policy does not support a `pass` action.

Additional resources

Understanding network policy APIs

AdminNetworkPolicy audit logging

Audit logging is enabled per AdminNetworkPolicy CR by annotating an ANP policy with the k8s.ovn.org/acl-logging key such as in the following example:

Example of annotation for AdminNetworkPolicy CR

apiVersion: policy.networking.k8s.io/v1alpha1
kind: AdminNetworkPolicy
metadata:
  annotations:
    k8s.ovn.org/acl-logging: '{ "deny": "alert", "allow": "alert", "pass" : "warning" }'
  name: anp-tenant-log
spec:
  priority: 5
  subject:
    namespaces:
      matchLabels:
        tenant: backend-storage # Selects all pods owned by storage tenant.
  ingress:
    - name: "allow-all-ingress-product-development-and-customer" # Product development and customer tenant ingress to backend storage.
      action: "Allow"
      from:
      - pods:
          namespaceSelector:
            matchExpressions:
            - key: tenant
              operator: In
              values:
              - product-development
              - customer
          podSelector: {}
    - name: "pass-all-ingress-product-security"
      action: "Pass"
      from:
      - namespaces:
          matchLabels:
              tenant: product-security
    - name: "deny-all-ingress" # Ingress to backend from all other pods in the cluster.
      action: "Deny"
      from:
      - namespaces: {}
  egress:
    - name: "allow-all-egress-product-development"
      action: "Allow"
      to:
      - pods:
          namespaceSelector:
            matchLabels:
              tenant: product-development
          podSelector: {}
    - name: "pass-egress-product-security"
      action: "Pass"
      to:
      - namespaces:
           matchLabels:
             tenant: product-security
    - name: "deny-all-egress" # egress from backend denied to all other pods.
      action: "Deny"
      to:
      - namespaces: {}

Logs are generated whenever a specific OVN ACL is hit and meets the action criteria set in your logging annotation. For example, an event in which any of the namespaces with the label tenant: product-development accesses the namespaces with the label tenant: backend-storage, a log is generated.

ACL logging is limited to 60 characters. If your ANP name field is long, the rest of the log will be truncated.

The following is a direction index for the examples log entries that follow:

Direction Rule

Direction	Rule
Ingress	Rule0 Allow from tenant `product-development` and `customer` to tenant `backend-storage`; Ingress0: `Allow` Rule1 Pass from product-security`to tenant `backend-storage; Ingress1: `Pass` Rule2 Deny ingress from all pods; Ingress2: `Deny`
egress	Rule0 Allow to `product-development`; egress0: `Allow` Rule1 Pass to `product-security`; egress1: `Pass` Rule2 Deny egress to all other pods; egress2: `Deny`

Ingress

Rule0: Allow from tenant product-development and customer to tenant backend-storage; Ingress0: Allow
Rule1: Pass from product-security`to tenant `backend-storage; Ingress1: Pass
Rule2: Deny ingress from all pods; Ingress2: Deny

egress

Rule0: Allow to product-development; egress0: Allow
Rule1: Pass to product-security; egress1: Pass
Rule2: Deny egress to all other pods; egress2: Deny

Example ACL log entry for Allow action of the AdminNetworkPolicy named anp-tenant-log with Ingress:0 and egress:0

2024-06-10T16:27:45.194Z|00052|acl_log(ovn_pinctrl0)|INFO|name="ANP:anp-tenant-log:Ingress:0", verdict=allow, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:80:02:1a,dl_dst=0a:58:0a:80:02:19,nw_src=10.128.2.26,nw_dst=10.128.2.25,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=57814,tp_dst=8080,tcp_flags=syn
2024-06-10T16:28:23.130Z|00059|acl_log(ovn_pinctrl0)|INFO|name="ANP:anp-tenant-log:Ingress:0", verdict=allow, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:80:02:18,dl_dst=0a:58:0a:80:02:19,nw_src=10.128.2.24,nw_dst=10.128.2.25,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=38620,tp_dst=8080,tcp_flags=ack
2024-06-10T16:28:38.293Z|00069|acl_log(ovn_pinctrl0)|INFO|name="ANP:anp-tenant-log:egress:0", verdict=allow, severity=alert, direction=from-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:80:02:19,dl_dst=0a:58:0a:80:02:1a,nw_src=10.128.2.25,nw_dst=10.128.2.26,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=47566,tp_dst=8080,tcp_flags=fin|ack=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=55704,tp_dst=8080,tcp_flags=ack

Example ACL log entry for Pass action of the AdminNetworkPolicy named anp-tenant-log with Ingress:1 and egress:1

2024-06-10T16:33:12.019Z|00075|acl_log(ovn_pinctrl0)|INFO|name="ANP:anp-tenant-log:Ingress:1", verdict=pass, severity=warning, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:80:02:1b,dl_dst=0a:58:0a:80:02:19,nw_src=10.128.2.27,nw_dst=10.128.2.25,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=37394,tp_dst=8080,tcp_flags=ack
2024-06-10T16:35:04.209Z|00081|acl_log(ovn_pinctrl0)|INFO|name="ANP:anp-tenant-log:egress:1", verdict=pass, severity=warning, direction=from-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:80:02:19,dl_dst=0a:58:0a:80:02:1b,nw_src=10.128.2.25,nw_dst=10.128.2.27,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=34018,tp_dst=8080,tcp_flags=ack

Example ACL log entry for Deny action of the AdminNetworkPolicy named anp-tenant-log with egress:2 and Ingress2

2024-06-10T16:43:05.287Z|00087|acl_log(ovn_pinctrl0)|INFO|name="ANP:anp-tenant-log:egress:2", verdict=drop, severity=alert, direction=from-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:80:02:19,dl_dst=0a:58:0a:80:02:18,nw_src=10.128.2.25,nw_dst=10.128.2.24,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=51598,tp_dst=8080,tcp_flags=syn
2024-06-10T16:44:43.591Z|00090|acl_log(ovn_pinctrl0)|INFO|name="ANP:anp-tenant-log:Ingress:2", verdict=drop, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:80:02:1c,dl_dst=0a:58:0a:80:02:19,nw_src=10.128.2.28,nw_dst=10.128.2.25,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=33774,tp_dst=8080,tcp_flags=syn

The following table describes ANP annotation:

Table 3. Audit logging AdminNetworkPolicy annotation
Annotation	Value
`k8s.ovn.org/acl-logging`	You must specify at least one of `Allow`, `Deny`, or `Pass` to enable audit logging for a namespace. `Deny` Optional: Specify `alert`, `warning`, `notice`, `info`, or `debug`. `Allow` Optional: Specify `alert`, `warning`, `notice`, `info`, or `debug`. `Pass` Optional: Specify `alert`, `warning`, `notice`, `info`, or `debug`.

BaselineAdminNetworkPolicy audit logging

Audit logging is enabled in the BaselineAdminNetworkPolicy CR by annotating an BANP policy with the k8s.ovn.org/acl-logging key such as in the following example:

Example of annotation for BaselineAdminNetworkPolicy CR

apiVersion: policy.networking.k8s.io/v1alpha1
kind: BaselineAdminNetworkPolicy
metadata:
  annotations:
    k8s.ovn.org/acl-logging: '{ "deny": "alert", "allow": "alert"}'
  name: default
spec:
  subject:
    namespaces:
      matchLabels:
          tenant: workloads # Selects all workload pods in the cluster.
  ingress:
  - name: "default-allow-dns" # This rule allows ingress from dns tenant to all workloads.
    action: "Allow"
    from:
    - namespaces:
          matchLabels:
            tenant: dns
  - name: "default-deny-dns" # This rule denies all ingress from all pods to workloads.
    action: "Deny"
    from:
    - namespaces: {} # Use the empty selector with caution because it also selects OpenShift namespaces as well.
  egress:
  - name: "default-deny-dns" # This rule denies all egress from workloads. It will be applied when no ANP or network policy matches.
    action: "Deny"
    to:
    - namespaces: {} # Use the empty selector with caution because it also selects OpenShift namespaces as well.

In the example, an event in which any of the namespaces with the label tenant: dns accesses the namespaces with the label tenant: workloads, a log is generated.

The following is a direction index for the examples log entries that follow:

Direction Rule

Direction	Rule
Ingress	Rule0 Allow from tenant `dns` to tenant `workloads`; Ingress0: `Allow` Rule1 Deny to tenant `workloads` from all pods; Ingress1: `Deny`
egress	Rule0 Deny to all pods; egress0: `Deny`

Ingress

Rule0: Allow from tenant dns to tenant workloads; Ingress0: Allow
Rule1: Deny to tenant workloads from all pods; Ingress1: Deny

egress

Rule0: Deny to all pods; egress0: Deny

Example ACL allow log entry for Allow action of default BANP with Ingress:0

2024-06-10T18:11:58.263Z|00022|acl_log(ovn_pinctrl0)|INFO|name="BANP:default:Ingress:0", verdict=allow, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:82:02:57,dl_dst=0a:58:0a:82:02:56,nw_src=10.130.2.87,nw_dst=10.130.2.86,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=60510,tp_dst=8080,tcp_flags=syn
2024-06-10T18:11:58.264Z|00023|acl_log(ovn_pinctrl0)|INFO|name="BANP:default:Ingress:0", verdict=allow, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:82:02:57,dl_dst=0a:58:0a:82:02:56,nw_src=10.130.2.87,nw_dst=10.130.2.86,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=60510,tp_dst=8080,tcp_flags=psh|ack
2024-06-10T18:11:58.264Z|00024|acl_log(ovn_pinctrl0)|INFO|name="BANP:default:Ingress:0", verdict=allow, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:82:02:57,dl_dst=0a:58:0a:82:02:56,nw_src=10.130.2.87,nw_dst=10.130.2.86,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=60510,tp_dst=8080,tcp_flags=ack
2024-06-10T18:11:58.264Z|00025|acl_log(ovn_pinctrl0)|INFO|name="BANP:default:Ingress:0", verdict=allow, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:82:02:57,dl_dst=0a:58:0a:82:02:56,nw_src=10.130.2.87,nw_dst=10.130.2.86,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=60510,tp_dst=8080,tcp_flags=ack
2024-06-10T18:11:58.264Z|00026|acl_log(ovn_pinctrl0)|INFO|name="BANP:default:Ingress:0", verdict=allow, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:82:02:57,dl_dst=0a:58:0a:82:02:56,nw_src=10.130.2.87,nw_dst=10.130.2.86,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=60510,tp_dst=8080,tcp_flags=fin|ack
2024-06-10T18:11:58.264Z|00027|acl_log(ovn_pinctrl0)|INFO|name="BANP:default:Ingress:0", verdict=allow, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:82:02:57,dl_dst=0a:58:0a:82:02:56,nw_src=10.130.2.87,nw_dst=10.130.2.86,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=60510,tp_dst=8080,tcp_flags=ack

Example ACL allow log entry for Allow action of default BANP with egress:0 and Ingress:1

2024-06-10T18:09:57.774Z|00016|acl_log(ovn_pinctrl0)|INFO|name="BANP:default:egress:0", verdict=drop, severity=alert, direction=from-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:82:02:56,dl_dst=0a:58:0a:82:02:57,nw_src=10.130.2.86,nw_dst=10.130.2.87,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=45614,tp_dst=8080,tcp_flags=syn
2024-06-10T18:09:58.809Z|00017|acl_log(ovn_pinctrl0)|INFO|name="BANP:default:egress:0", verdict=drop, severity=alert, direction=from-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:82:02:56,dl_dst=0a:58:0a:82:02:57,nw_src=10.130.2.86,nw_dst=10.130.2.87,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=45614,tp_dst=8080,tcp_flags=syn
2024-06-10T18:10:00.857Z|00018|acl_log(ovn_pinctrl0)|INFO|name="BANP:default:egress:0", verdict=drop, severity=alert, direction=from-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:82:02:56,dl_dst=0a:58:0a:82:02:57,nw_src=10.130.2.86,nw_dst=10.130.2.87,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=45614,tp_dst=8080,tcp_flags=syn
2024-06-10T18:10:25.414Z|00019|acl_log(ovn_pinctrl0)|INFO|name="BANP:default:Ingress:1", verdict=drop, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:82:02:58,dl_dst=0a:58:0a:82:02:56,nw_src=10.130.2.88,nw_dst=10.130.2.86,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=40630,tp_dst=8080,tcp_flags=syn
2024-06-10T18:10:26.457Z|00020|acl_log(ovn_pinctrl0)|INFO|name="BANP:default:Ingress:1", verdict=drop, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:82:02:58,dl_dst=0a:58:0a:82:02:56,nw_src=10.130.2.88,nw_dst=10.130.2.86,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=40630,tp_dst=8080,tcp_flags=syn
2024-06-10T18:10:28.505Z|00021|acl_log(ovn_pinctrl0)|INFO|name="BANP:default:Ingress:1", verdict=drop, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:82:02:58,dl_dst=0a:58:0a:82:02:56,nw_src=10.130.2.88,nw_dst=10.130.2.86,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=40630,tp_dst=8080,tcp_flags=syn

The following table describes BANP annotation:

Table 4. Audit logging BaselineAdminNetworkPolicy annotation
Annotation	Value
`k8s.ovn.org/acl-logging`	You must specify at least one of `Allow` or `Deny` to enable audit logging for a namespace. `Deny` Optional: Specify `alert`, `warning`, `notice`, `info`, or `debug`. `Allow` Optional: Specify `alert`, `warning`, `notice`, `info`, or `debug`.

Configuring egress firewall and network policy auditing for a cluster

As a cluster administrator, you can customize audit logging for your cluster.

Prerequisites

Install the OpenShift CLI (oc).
Log in to the cluster with a user with cluster-admin privileges.

Procedure

To customize the audit logging configuration, enter the following command:

$ oc edit network.operator.openshift.io/cluster

You can alternatively customize and apply the following YAML to configure audit logging:

apiVersion: operator.openshift.io/v1
kind: Network
metadata:
  name: cluster
spec:
  defaultNetwork:
    ovnKubernetesConfig:
      policyAuditConfig:
        destination: "null"
        maxFileSize: 50
        rateLimit: 20
        syslogFacility: local0

Verification

To create a namespace with network policies complete the following steps:

Create a namespace for verification:

$ cat <<EOF| oc create -f -
kind: Namespace
apiVersion: v1
metadata:
  name: verify-audit-logging
  annotations:
    k8s.ovn.org/acl-logging: '{ "deny": "alert", "allow": "alert" }'
EOF

Example output

namespace/verify-audit-logging created

Create network policies for the namespace:

$ cat <<EOF| oc create -n verify-audit-logging -f -
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: deny-all
spec:
  podSelector:
    matchLabels:
  policyTypes:
  - Ingress
  - egress
---
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: allow-from-same-namespace
  namespace: verify-audit-logging
spec:
  podSelector: {}
  policyTypes:
   - Ingress
   - egress
  ingress:
    - from:
        - podSelector: {}
  egress:
    - to:
       - namespaceSelector:
          matchLabels:
            kubernetes.io/metadata.name: verify-audit-logging
EOF

Example output

networkpolicy.networking.k8s.io/deny-all created
networkpolicy.networking.k8s.io/allow-from-same-namespace created

Create a pod for source traffic in the default namespace:

$ cat <<EOF| oc create -n default -f -
apiVersion: v1
kind: Pod
metadata:
  name: client
spec:
  containers:
    - name: client
      image: registry.access.redhat.com/rhel7/rhel-tools
      command: ["/bin/sh", "-c"]
      args:
        ["sleep inf"]
EOF

Create two pods in the verify-audit-logging namespace:

$ for name in client server; do
cat <<EOF| oc create -n verify-audit-logging -f -
apiVersion: v1
kind: Pod
metadata:
  name: ${name}
spec:
  containers:
    - name: ${name}
      image: registry.access.redhat.com/rhel7/rhel-tools
      command: ["/bin/sh", "-c"]
      args:
        ["sleep inf"]
EOF
done

Example output

pod/client created
pod/server created

To generate traffic and produce network policy audit log entries, complete the following steps:

Obtain the IP address for pod named server in the verify-audit-logging namespace:

$ POD_IP=$(oc get pods server -n verify-audit-logging -o jsonpath='{.status.podIP}')

Ping the IP address from the previous command from the pod named client in the default namespace and confirm that all packets are dropped:

$ oc exec -it client -n default -- /bin/ping -c 2 $POD_IP

Example output

PING 10.128.2.55 (10.128.2.55) 56(84) bytes of data.

--- 10.128.2.55 ping statistics ---
2 packets transmitted, 0 received, 100% packet loss, time 2041ms

Ping the IP address saved in the POD_IP shell environment variable from the pod named client in the verify-audit-logging namespace and confirm that all packets are allowed:

$ oc exec -it client -n verify-audit-logging -- /bin/ping -c 2 $POD_IP

Example output

PING 10.128.0.86 (10.128.0.86) 56(84) bytes of data.
64 bytes from 10.128.0.86: icmp_seq=1 ttl=64 time=2.21 ms
64 bytes from 10.128.0.86: icmp_seq=2 ttl=64 time=0.440 ms

--- 10.128.0.86 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1001ms
rtt min/avg/max/mdev = 0.440/1.329/2.219/0.890 ms

Display the latest entries in the network policy audit log:

$ for pod in $(oc get pods -n openshift-ovn-kubernetes -l app=ovnkube-node --no-headers=true | awk '{ print $1 }') ; do
    oc exec -it $pod -n openshift-ovn-kubernetes -- tail -4 /var/log/ovn/acl-audit-log.log
  done

Example output

2023-11-02T16:28:54.139Z|00004|acl_log(ovn_pinctrl0)|INFO|name="NP:verify-audit-logging:Ingress", verdict=drop, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:81:02:01,dl_dst=0a:58:0a:81:02:23,nw_src=10.131.0.39,nw_dst=10.129.2.35,nw_tos=0,nw_ecn=0,nw_ttl=62,nw_frag=no,tp_src=58496,tp_dst=8080,tcp_flags=syn
2023-11-02T16:28:55.187Z|00005|acl_log(ovn_pinctrl0)|INFO|name="NP:verify-audit-logging:Ingress", verdict=drop, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:81:02:01,dl_dst=0a:58:0a:81:02:23,nw_src=10.131.0.39,nw_dst=10.129.2.35,nw_tos=0,nw_ecn=0,nw_ttl=62,nw_frag=no,tp_src=58496,tp_dst=8080,tcp_flags=syn
2023-11-02T16:28:57.235Z|00006|acl_log(ovn_pinctrl0)|INFO|name="NP:verify-audit-logging:Ingress", verdict=drop, severity=alert, direction=to-lport: tcp,vlan_tci=0x0000,dl_src=0a:58:0a:81:02:01,dl_dst=0a:58:0a:81:02:23,nw_src=10.131.0.39,nw_dst=10.129.2.35,nw_tos=0,nw_ecn=0,nw_ttl=62,nw_frag=no,tp_src=58496,tp_dst=8080,tcp_flags=syn
2023-11-02T16:49:57.909Z|00028|acl_log(ovn_pinctrl0)|INFO|name="NP:verify-audit-logging:allow-from-same-namespace:egress:0", verdict=allow, severity=alert, direction=from-lport: icmp,vlan_tci=0x0000,dl_src=0a:58:0a:81:02:22,dl_dst=0a:58:0a:81:02:23,nw_src=10.129.2.34,nw_dst=10.129.2.35,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,icmp_type=8,icmp_code=0
2023-11-02T16:49:57.909Z|00029|acl_log(ovn_pinctrl0)|INFO|name="NP:verify-audit-logging:allow-from-same-namespace:Ingress:0", verdict=allow, severity=alert, direction=to-lport: icmp,vlan_tci=0x0000,dl_src=0a:58:0a:81:02:22,dl_dst=0a:58:0a:81:02:23,nw_src=10.129.2.34,nw_dst=10.129.2.35,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,icmp_type=8,icmp_code=0
2023-11-02T16:49:58.932Z|00030|acl_log(ovn_pinctrl0)|INFO|name="NP:verify-audit-logging:allow-from-same-namespace:egress:0", verdict=allow, severity=alert, direction=from-lport: icmp,vlan_tci=0x0000,dl_src=0a:58:0a:81:02:22,dl_dst=0a:58:0a:81:02:23,nw_src=10.129.2.34,nw_dst=10.129.2.35,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,icmp_type=8,icmp_code=0
2023-11-02T16:49:58.932Z|00031|acl_log(ovn_pinctrl0)|INFO|name="NP:verify-audit-logging:allow-from-same-namespace:Ingress:0", verdict=allow, severity=alert, direction=to-lport: icmp,vlan_tci=0x0000,dl_src=0a:58:0a:81:02:22,dl_dst=0a:58:0a:81:02:23,nw_src=10.129.2.34,nw_dst=10.129.2.35,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,icmp_type=8,icmp_code=0

Enabling egress firewall and network policy audit logging for a namespace

As a cluster administrator, you can enable audit logging for a namespace.

Prerequisites

Install the OpenShift CLI (oc).
Log in to the cluster with a user with cluster-admin privileges.

Procedure

To enable audit logging for a namespace, enter the following command:

$ oc annotate namespace <namespace> \
  k8s.ovn.org/acl-logging='{ "deny": "alert", "allow": "notice" }'

where:

<namespace>: Specifies the name of the namespace.

You can alternatively apply the following YAML to enable audit logging:

kind: Namespace
apiVersion: v1
metadata:
  name: <namespace>
  annotations:
    k8s.ovn.org/acl-logging: |-
      {
        "deny": "alert",
        "allow": "notice"
      }

Example output

namespace/verify-audit-logging annotated

Verification

Display the latest entries in the audit log:

$ for pod in $(oc get pods -n openshift-ovn-kubernetes -l app=ovnkube-node --no-headers=true | awk '{ print $1 }') ; do
    oc exec -it $pod -n openshift-ovn-kubernetes -- tail -4 /var/log/ovn/acl-audit-log.log
  done

Example output

2023-11-02T16:49:57.909Z|00028|acl_log(ovn_pinctrl0)|INFO|name="NP:verify-audit-logging:allow-from-same-namespace:egress:0", verdict=allow, severity=alert, direction=from-lport: icmp,vlan_tci=0x0000,dl_src=0a:58:0a:81:02:22,dl_dst=0a:58:0a:81:02:23,nw_src=10.129.2.34,nw_dst=10.129.2.35,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,icmp_type=8,icmp_code=0
2023-11-02T16:49:57.909Z|00029|acl_log(ovn_pinctrl0)|INFO|name="NP:verify-audit-logging:allow-from-same-namespace:Ingress:0", verdict=allow, severity=alert, direction=to-lport: icmp,vlan_tci=0x0000,dl_src=0a:58:0a:81:02:22,dl_dst=0a:58:0a:81:02:23,nw_src=10.129.2.34,nw_dst=10.129.2.35,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,icmp_type=8,icmp_code=0
2023-11-02T16:49:58.932Z|00030|acl_log(ovn_pinctrl0)|INFO|name="NP:verify-audit-logging:allow-from-same-namespace:egress:0", verdict=allow, severity=alert, direction=from-lport: icmp,vlan_tci=0x0000,dl_src=0a:58:0a:81:02:22,dl_dst=0a:58:0a:81:02:23,nw_src=10.129.2.34,nw_dst=10.129.2.35,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,icmp_type=8,icmp_code=0
2023-11-02T16:49:58.932Z|00031|acl_log(ovn_pinctrl0)|INFO|name="NP:verify-audit-logging:allow-from-same-namespace:Ingress:0", verdict=allow, severity=alert, direction=to-lport: icmp,vlan_tci=0x0000,dl_src=0a:58:0a:81:02:22,dl_dst=0a:58:0a:81:02:23,nw_src=10.129.2.34,nw_dst=10.129.2.35,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,icmp_type=8,icmp_code=0

Disabling egress firewall and network policy audit logging for a namespace

As a cluster administrator, you can disable audit logging for a namespace.

Prerequisites

Install the OpenShift CLI (oc).
Log in to the cluster with a user with cluster-admin privileges.

Procedure

To disable audit logging for a namespace, enter the following command:

$ oc annotate --overwrite namespace <namespace> k8s.ovn.org/acl-logging-

where:

<namespace>: Specifies the name of the namespace.

You can alternatively apply the following YAML to disable audit logging:

kind: Namespace
apiVersion: v1
metadata:
  name: <namespace>
  annotations:
    k8s.ovn.org/acl-logging: null

Example output

namespace/verify-audit-logging annotated